Cutter bar



CUTTER BAR original Filed May 24, 1955 -dllll-Il l w v l III I; 1 0 l lIIN 1 INVENTOR.

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Patented Feb. 22, 1938 UNITED STATES CUTTER BAR Charles L. Bowman,Canton, Ohio, assignor to The Bowdil Company, Canton, Ohio, acorporation of Ohio Original application May 24, 1935, Serial No.

Divided and this application December 12, 1935, Serial No. 54,998

4 Claims.

My invention relates in general to mining machines, and moreparticularly to cutter bars and tooth carrying chains.

This application is a division of my application, Serial Number 23,211,filed May 24, 1935 for Mining machines.

In the mining of coal, the cutter bar and the tooth carrying chain cutsa cleft in the lower level of the Vein of coal, and forms a shelf whichis subsequently broken off by means of explosives or other suitablemethods. When cutting the cleft, in the interest of economy, it ishighly desirable that the depth of the cleft or cut be as narrow aspossible, because the cut-away coal is of no commercial value.Furthermore, it is highly essential that the depth of the cleft cut inthe vein of coal be as narrow as possible; because, nowadays, the coalmines have been exhausted to the point that it is necessary to mine muchnarrower veins than formerly necessary. Thus, if the coal vein is onlythree or four feet thick, and if the width of the cut in the cleft is asmuch as six or seven inches, there is a considerably high percentage ofloss resulting from the relatively wide cut.

Therefore, an object of my invention is the provision of a relativelythin and solid cutter bar which cuts a very narrow cleft in the vein ofcoal.

Another object of my invention is the provision of a solid cutter barthat is relatively thin and iexible and that has a variable sectionmodulus to prevent the concentration of stresses as the bar is flexed.

A still further object of my invention is the provision of slidablymounting and slidably adjusting the cutter bar relative to the drivingsprocket which drives the tooth carrying chain, so as to take care ofthe slack in the tooth carrying chain and to keep the tooth carryingchain in the guide channel of the cutter bar.

Another object of my invention is the provision of a tooth carryingchain made up in sections having progressively staggered teeth, whichout a cleft in the vein of coal that is wider than the width of thecutter bar, so as to allow the cutter bar to enter freely in the cleftas it is cut by the tooth carrying chain.

Another object of my invention is the provision of a tooth carryingchain made up of alternatelyr connected female and male body links, thearrangement of the female and male body links being such that there isprovided a chain socket to straddle the sprocket teeth of the drivingsprocket.

Other objects and a fuller understanding of my invention may be had byreferring to the following description and claims, taken in conjunctionwith the accompanying drawing, in which:

Figure l represents a longitudinalr plan View of la cutter bar embodyingthe features of my invention, taken in combination with the ,driving vsprocket which drives a tooth carrying chainin the guide channel of thecutter bar; i

Figure 2 represents a longitudinalvcross-sectional View of the cutterbar and driving sprocket, taken along the line 2 2 of Figure 1;

Figure 3 represents a longitudinal plan -view of a single section of thetooth carrying chain;V`

Figure 4 is a longitudinal perspective View of a cutter bar embodyingthe features ofmy invention; and

Figure 5 represents a side elevational view of one of the body links,illustrating a replaceable cutting tooth. f f.

With reference to the drawing, mycutter vbar is indicated generally bythe reference character Ill and is adaptedto be heldin operatingalignment with a driving sprocket, indicated by the reference character2Il'which drives a tooth carrying chain, indicated'generally bythereference character 28. In the practice of Vmy invention, the cutter barII) may beconstructed of one solid piece of steel such as by casting thecutter bar. After the cutter bar is cast, thereismilledf a guide channelII on opposite sides of the cutter bar which receives the tooth carryingchain 2S. At the forward or free end of the cutter bar, the guidechannel I I is cut deep at right angles, along the line indicated by thereference character I4. After the deep channel around the end of thecutte;1 bar II) is cut out, there is positioned in this deep forwardchannel a substantially'semi-circular wear resisting member l2,which-may 'be held in position by means of suitable rivets I3. In thismanner there is provided a guide channelV II for the tooth carryingchain 28 around the forward end of the cutter bar, as well as along theopposite sides thereof. The wear resisting member` I2 prevents theforward end of the cutter bar from rapidly wearing away. Then too, aftera considerable length of time, if the wear resistingmember I2 itselfwears away, it maybe replaced by a new wear resisting member, thisavoiding the necessity of discarding the entire cutter bar.

The cutter bar ID is slidably mounted relative to the driving sprocket2l). To take care of slidable longitudinal adjustments, there yisprovided upon the rearward end of the cutter bar I,l3,a lug I1, throughwhich a threaded adjusting bolt I B extends. As illustrated, the end of,said bolt I8 has a head for rotatively engaging asocketgin a .centrationlof .the bending stresses.

Aof .the .cutter bar.

boss 23 upon the mining machine. Therefore, by turning the adjustingscrew I8, the cutter bar I0 is moved longitudinally relative to thedriving sprocket 20. This adjustment takes care of the slack in thetooth cutting chain 28 and keeps the tooth cutting chain within theguide channel II, Also this longitudinal adjustment lprovided bythescrew I8 affords a means for mounting Yor dismounting the chain from thecutter bar I0. In order that the rear end of the cutter bar I D maybedrawn as closely as possible to the driving sprocket 20, the rearwardcentral end of the cutter bar I0 is recessed, such as indicated by thereference character I9.

When cutting coal, the cutter bar I0 is frequently subjected to largebending stresses which tend to bend the cutter bar beyond its yieldingpoint, so that when the bar is free it may not return to its originalstraight position. Therefore, in the construction of my cutter bar, Iprovide for carrying ,the section modulus ofthe cutter bar in order toavoid this `bending caused by the'con- To accomplish a variable .sectionmodulus, I provide longitudinal depressions I5 `and I6 on opposite sidesThe width -of these depressions I5 and I6, as 4well as the depth,increases ltowards the free rend -of .the cutter bar. YIn other words,the section modulus is small at .the free end of the cutter :bar and:gradually increases .to a larger Value towards the rear end of thecutter ba-r. This means thatthe .cutter bar is relatively flexible andythus may be flexed a considerable amount, Without permanently Ybendingthe bar, such as caused by the large concentration Yof stresses. Byvmakin-g a depression I5 and I6 upon each side of the cutter bar I0, itis not necessary to make the depressions very deep, as would be the caseif the depression were only on Yone side. Then too, by having adepression upon each side, the neutral bending axis of the cutter bar isdirectly in the middle of lthe cutter bar. This means .that there is nounequal distribution of stresses when the cutter bar is bent eitherupwardly or downwardly.

The tooth carrying chain 28 is made up of a plurality of sections, acomplete section is shown in Figure 3, and comprises six body links.Each link is arranged to carry a replaceable cutting tooth 45 held inplace by a lug 46 and a cap screw 41. In each section, the body linksare progressively staggered, so that each cutting tooth 45, carried bythe successive body links, cuts at a different place in the cleft of thecoal vein. The body links, ofthe single section, shown in Figure 3, aredesignated by the reference characters 29, 30, 3|, 32, 33, and 34. Thewidth of the cleft is determined by the lateral staggered positions ofthe cutting teeth45 carried by the two outside body links 30 and 29 ofeachsection of the tooth carrying chain 28, and is of suchvalue that thewidth of the cleft is wider than the width of the cutter bar I0, so asto allow the cutter bar to enter freely in the cleft as it is cut bythecutting teeth of the progressively staggered sections.

The tooth carrying chain 28 is constructed of alternately interconnectedmale and female body links. With reference to Figure 3, the body linksdesignated by the reference 'characters 29, 3I, and 33', are female, andthe body links designated by the reference characters 3U, 32, and 34,are male. The lower part of the female body link is provid-ed with two,spaced side members 38 and 39,Which are an integral part of the entirebody link. The lower part of the male link is provided with a singleinterconnecting member 31 which ts between the ends of the two spacedmembers 38 and 39, and is connected thereto by a rivet pin 36. In orderto prevent excessive wear, I employ a case hardened bushing 3'5 in themale links, through which the chain pin 36 extends. The chain pin 36 `isprevented from rotating within the two side members 38 and 39 of thefemale link, so that the entire rctational movement takes place betweenthe pin 36 and the case hardened bushing 35 in the male links, throughwhich the chain pin 36 extends. 'I'he arrangement of the two sidemembers 38 and 39 ofthe female links and the interconnected member 37 ofthe male links is such that there vis provided a chain socket whichstraddles the sprocket teeth 2| of the driving sprocket 20. In thismanner each link of the chain is used as a cutting link and produces agreater efliciency -i'n cutting operation.

Although I have described my' invention with a certain degree ofparticularity, it is understood that the present disclosure has beenmade only by way of example vand that numerous changes in the details-o-f construction and the combination and arrangement of parts may beresorted to without 'departing from the spirit and the scope of theinvention as hereinafter claimed.

I claim as my invention:

l. In a'mining machine, a solid cutter bar having a guide channel initsopposite edges and a deepchannel extending around the forward end ofthe bar, said deep channel having a bottom surface disposed angularlywith referenceto the bottom surface of the two opposite guide channels,a wear resisting member having a forward arcuate surface and a rearwardengaging surface to engage the angular bottom surface of the deepchannel, transversely extending means engaging the wear resisting memberand the sides of the deep channel for securely mounting the wearresisting member in the deep channel upon the forward end of the .cutterbar, the width of the rearward surface of the wear resisting memberbeing substantially the same as the width between the bottom surfaces ofthe two opposite guide channels and causing the arcuate surface to formthe bottom of a guide channel extending around the forward end of thecutter bar of substantially the same depth as the depth of each of thetwo opposite guide channels.

2. In a mining machine, a solid cutter bar having a guide channel in itsopposite edges and a deep channel extending around the forward end ofthe bar, said deep channel having a bottom surface disposed angularlywith reference to the bottom surface of the two opposite guide channels,a wear resisting member having a forward arcuate surface and a rearwardengaging surface to engage the angular bottom surface of the deepchannel, transversely extending means engaging the wear resisting memberand the sides of the deep channel for securely mounting the wearresisting member in the deep channel upon the forward end of the cutterbar, the width of the rearward surface of the wear resisting memberbeing substantially the same as the width between the bottom surfaces ofthe two opposite guide channels and causing the arcuate surface to formthe bottom of a guide channel extending around the forward end of thecutter bar of substantially the same depth as the depth of each of thetwo opposite guide channels, a tooth carrying chain operating in thechannel, driving means for driving the chain, means for slidablymounting the cutter bar in alignment with the driving means, andadjusting means for slidably moving the cutter bar relative to thedriving means to take care of slack in the tooth carrying chain and tokeep the chain in the guide channel.

3. In a mining machine, a solid cutter bar having a guide channel in itsopposite edges and a deep channel extending around the forward end ofthe bar, said deep channel having a bottom surface disposed angularlywith reference to the bottom surface of the two opposite guide channels,a wear resisting member having a forward arcuate surface and a rearwardengaging surface to engage the angular bottom surface of the deepchannel, transversely extending means engaging the wear resisting memberand the sides of the deep channel for securely mounting the wearresisting member in the deep channel upon the forward end of the cutterbar, the width of the rearward surface of the wear resisting memberbeing substantially the same as the width between the bottom Asurfacesof the two opposite guide channels and causing the arcuate surface toform the bottom of a guide channel extending around the forward end ofthe cutter bar of substantially the same depth as the depth of each ofthe two opposite guide channels, a tooth carrying chain operating in thechannel, driving means for driving the chain, means for slidablymounting the cutter bar in alignment with the driving means, andadjusting means for slidably moving the cutter bar relative to thedriving means to take care of slack in the tooth carrying chain and tokeep the chain in the guide channel, the cutter bar being relativelythin and flexible and having a variable longitudinal depressed surfaceon opposite sides thereof to give a variable section modulus to preventthe concentration of stresses as the bar is flexed and to make theneutral bending axis in substantially the longitudinal center of thecutter bar.

4. In a mining machine, a cutter bar having a guide channel in itsopposite edges and adeep channel extending around the forward end of thebar, said deep channel having a bottom surface disposed angularly withreference to the bottom surface of the two opposite guide channels, awear resisting member having a forward arcuate surface and a rearwardengaging surface to engage the angular bottom surface of the deepchannel, means engaging the wear resisting member and the cutter bar forsecurely mounting the wear resisting member in the deep channel upon theforward end of the cutter bar, the width of the rearward surface of thewear resisting member being substantially the same as the width betweenthe bottom surfaces of the two opposite guide channels and causing thearcuate surface to form the bottom of a guide channel extending aroundthe forward end of the cutter bar of substantially the same depth as thedepth of each of the two opposite guide channels.

CHARLES L. BOWMAN.

